Filter assembly and method

ABSTRACT

A filter assembly having a filter head having inlet and outlet ports and a top cap having a substantially curved, non-planar flange portion, the non-planar flange sealingly received within the filter head such that the filter head is divided into inlet and outlet partitions. In some embodiments, the flange portion has a generally s-shaped cross-sectional profile. The flange portion incorporating a modified venturi for improved flow of both inlet and outlet streams through the filter assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/826,474 filed Jul. 16, 2007, U.S. Pat. No. 7,618,480, the contents ofwhich is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

This invention relates generally to a filter assembly and method forimproving flow through the assembly. More particularly, the presentinvention relates, for example, to a fluid filter assembly having anon-planar flange for directing flow through the assembly.

BACKGROUND OF THE INVENTION

It is known in the art that hydraulic and pneumatic filters may be usedto remove particulates, oils and water vapor from fluid mixtures. Thesefilters may also be used to remove odors from breathing air. It is knownin the art that compressed air, which has several uses including in foodpackaging, pharmaceutical labs and integrated circuit manufacturing, maybe treated to remove contaminants and water vapor. For instance, incircuit design, it is critical for the compressed air to be devoid ofoils and water vapor which can cause a short circuit. Compressed air istreated before use in manufacturing systems to remove water vapor andcontaminants from the air that may spoil the end product or at leastincrease the cost of production by robbing the system of power andefficiency.

Conventional filters, which are used in various applications such as intreating compressed air, may contain a two-piece housing including afilter head and an elongated tubular filter housing. An elongatedtubular element is typically removably located within the housing, thetubular elements having annular end caps sealingly bonded at each end ofa ring-shaped media. These filters also include a diverter or elbowstructure which may direct flow into the filter and provide a means forseparating the head casting into inlet and outlet streams, respectivelyconnected to the inner and outer portions of the elongated tubularelement.

More recently, filters have utilized a top cap that serves the functionof a diverter. These top caps may have a truncated funnel-likeconfiguration removably located within a cylindrical cavity of the headcasting. The flow passes through the filter element, which may consistof a media or membrane designed to prevent undesired substances fromflowing through the element into the filtrate product stream.Accordingly, filtrate that flows through the media then continuesthrough the outlet port within the head casting. In coalescing filters,the media causes certain condensed liquid components to coalesce andcombine the coalesced droplets out of the gaseous product stream whilesolid particles are trapped by sieving, impaction or Brownian motion.

The shape of the inlet-side surface of the top cap controls the flowgeometry of the inlet flow into the element. Similarly, the outlet-sidesurface of the top cap controls the outlet flow. When the inlet streamdirectly impacts a wall portion of the top cap, the impact causesturbulence in the fluid flow. As a result, the kinetic energy of thefluid is decreased which increases the velocity of the fluid as itenters the filter element. These filters have included a top cap havinga planar flange section which affects inlet flow from the head castinginto the filter element. The flange may tend to reduce the effects ofturbulence by decreasing the energy of the fluid and disturbing thevelocity of the fluid as it enters the filter element. However, theplanar flange may still result in turbulent flow in the inlet and outletstreams.

Accordingly, it is desirable to provide a fluid filter assembly having aflange which has inlet-side and outlet-side surfaces that enable morelaminar flow of fluid directly into and out of the filter assembly. Itis desirable to decrease turbulence because of the pressure drop andalso because turbulence causes re-entrainment of condensed fluid incoalescing filters.

SUMMARY OF THE INVENTION

The foregoing needs are met, to a great extent, by the presentinvention, wherein aspects of a fluid filter assembly having anon-planar flange portion may be used for directing flow through theassembly. Example embodiments of the present invention provide improvedflow through a filter element top cap that to a greater extentincorporates a “modified venturi” having a generally diagonal entrancewith non-planar surface facing the process flow inlet for in-to-out flowthrough the element. As such, the novel top cap allows for a smoothertransition into the media resulting in lower overall pressure loss. Thefluid filter assembly of the present invention enables an inletconnection that directs the process gas directly into the vessel withoutthe use of an elbow or diverter or other similar flow restrictiondevice.

Example embodiments of the present invention relate to a filter assemblyhaving a filter head having inlet and outlet ports and a top cap havinga substantially curved, non-planar flange portion, the non-planar flangesealingly received within the filter head such that the filter head isdivided into inlet and outlet partitions. The flange portion mayincorporate a modified venturi for improved flow of both inlet andoutlet streams through the filter assembly. In some embodiments, theflange portion has a generally s-shaped cross-sectional profile. Inexample embodiments, the non-planar flange is sealingly received withinthe filter head such that the filter head is divided into inlet andoutlet partitions; wherein the top cap directs fluid from the inlet portinto the filter element, where the fluid flows through the barrier offiltration media and then out of the assembly through the outlet port.

The filter assembly may also include a filter head having inlet andoutlet ports; a filter element housed within a filter bowl, wherein apressure differential exists across the filter element. The filterelement may include a barrier of filtration media, a drain layer and atleast one support tube. In example embodiments, a compression tabconfigured to maintain a compression seal between the filter head andthe top cap may be used. A compression tab may also be configured toposition the filter element.

In example embodiments of the present invention, the inlet and outletports of the filter assembly may be generally inline with one another,which is preferable in compressed gas applications. The assembly mayalso include a pressure gauge having pressure sensors attached to thefilter head for measuring the pressure differential across the filterelement. The filter head could include sensor ports for attaching thepressure sensors within the filter head. In example embodiments, thefilter bowl is in threaded attachment with the filter head. The filterbowl may then include outer ribs running along an outside surface of thefilter bowl for improved hand tightening and loosening of the threadedattachment. The filter head may include a slanted inner top surface fordecreasing a volume of the filter head, which is preferable in certainapplications.

In example embodiments of the present invention, the filter bowlincludes inner ribs running axially along an inside surface of thefilter bowl for capillary draining of liquid drops that escape the drainlayer. The filter bowl may include an o-ring groove located along anupper outer surface of the filter bowl for forming a pressurizedattachment between the filter bowl and the filter head. This o-ring sealisolates the threads from the fluid reducing the possible corrosiveeffect on the threads. Additionally, the filter bowl may include abaffle located along a bottom inner portion of the filter bowl forquieting the gas to minimize re-entrainment of coalesced liquids. Thefilter bowl may also include a sight glass for viewing the fluid level.

In some embodiments of the filter assembly of the present invention, acosmetic cover is configured to mate with a top outer surface of thefilter head. When it is desirable to use more than one filtrationapparatus, at least one ganging clamp may be used for connecting thefilter assembly to at least one other filtration apparatus.

Further contemplating in this invention is a method of directing flowthrough a filter assembly, comprising: directing flow of a fluid into aninlet port located within a filter head of the filter assembly; passingthe fluid from the inlet port into a filter element using a top caphaving a substantially curved, non-planar flange portion, wherein thenon-planar flange portion is sealingly received within the filter headsuch that the filter head is divided into inlet and outlet partitions;and passing the fluid out of the assembly through the outlet port.

The method of directing flow through a filter assembly may also includemeasuring the pressure differential across the filter element. Themethod of directing flow through a filter assembly may also includecapillary draining of liquid drops that escape the drain layer usinginner ribs running axially along an inside surface of the filter bowl.The method of directing flow through a filter assembly may also includehand tightening of the filter bowl to the filter head using outer ribsrunning along an outside surface of the filter bowl. Furthermore, apressurized attachment between the filter bowl and the filter head maybe formed.

In example embodiments of the method of directing flow through a filterassembly in accordance with the present invention, the method alsoincludes minimizing re-entrainment of coalesced fluid using a bafflelocated along the bottom inner portion of the filter bowl. The methodmay also include connecting the filter assembly to at least one otherfiltration apparatus using a plurality of ganging clamps that align thevarious filter housings. The method may also include clipping the filterelement using one or more compression tab(s) and sealing the filter headto the top cap using compression tab(s).

In example embodiments of the present invention, a filter assembly mayinclude: filter head means for containing inlet and outlet ports; filterelement means for filtration of a fluid; filter bowl means for housingthe filter element, wherein the filter bowl means is attached to thefilter head means; and top cap means for dividing the filter head intoinlet and outlet partitions; wherein the top cap means includes asubstantially curving non-planar flange portion, wherein the non-planarflange is sealingly received within the filter head.

There has thus been outlined, rather broadly, certain embodiments of theinvention in order that the detailed description thereof herein may bebetter understood, and in order that the present contribution to the artmay be better appreciated. There are, of course, additional embodimentsof the invention that will be described below and which will form thesubject matter of the claim appended hereto.

In this respect, before explaining at least one embodiment of theinvention in detail, it is to be understood that the invention is notlimited in its application to the details of construction and to thearrangements of the components set forth in the following description orillustrated in the drawings. The invention is capable of embodiments inaddition to those described and of being practiced and carried out invarious ways. Also, it is to be understood that the phraseology andterminology employed herein, as well as the abstract, are for thepurpose of description and should not be regarded as limiting.

As such, those skilled in the art will appreciate that the conceptionupon which this disclosure is based may readily be utilized as a basisfor the designing of other structures, methods and systems for carryingout the several purposes of the present invention. It is important,therefore, that the claims be regarded as including such equivalentconstructions insofar as they do not depart from the spirit and scope ofthe present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a filter assembly having anon-planar flange, according to an embodiment of the present invention.

FIG. 2 provides an exploded view of the inner components of the filterassembly of FIG. 1.

FIG. 3A provides a plan view of the filter assembly of FIG. 1.

FIG. 3B provides a plan view of the filter assembly of FIG. 1 withoutthe differential pressure gauge.

FIG. 4A provides an angled plan view of the top of the filter head ofthe filter assembly of FIG. 1.

FIG. 4B provides an angled plan view of the bottom of the filter head ofthe filter assembly of FIG. 1.

FIG. 5 provides a perspective view of a cosmetic cap for the filterassembly of FIG. 1.

FIG. 6A provides a partially cutaway view of the interior of the filterbowl of the filter assembly of FIG. 1.

FIG. 6B provides a frontal view of the exterior of the filter bowl ofthe filter assembly of FIG. 1.

FIG. 6C provides a topical view of the interior of the filter bowl ofthe filter assembly of FIG. 1.

FIG. 7 provides a plan view of the filter assembly of FIG. 1 havingganging clamps attached to the inlet and outlet ports.

DETAILED DESCRIPTION

Various embodiments of the present invention provide for a fluid filterassembly having a non-planar flange portion for directing flow directlyinto the assembly without the use of an elbow or similar flowrestriction device. In some arrangements, the present invention may beutilized in a compressed air or gas system, for example. It should beunderstood, however, that the present invention is not limited in itsapplication to compressed air systems, but may have application in otherfluid separation systems that utilize a filter assembly having a headcontaining both inlet and outlet ports. Embodiments of the inventionwill now be further described with reference to the drawing figures, inwhich like reference numbers refer to like parts throughout.

FIG. 1 is a cross-sectional view of the filter assembly 100, accordingto an embodiment of the present invention. In example embodiments of thepresent invention, filter assembly 100 having a non-planar flangeportion 105 is provided. Example embodiments of the filter assembly 100include a filter bowl 115, a tapered filter head 120, a top cap 135having a non-planar flange portion 105, a bottom cap 150, and a filterelement 110, which includes: a filter media 112 surrounded by supporttubes 140, and a drain layer 117, which is the outer most layer of thefilter element 110. Additionally, a float drain 141 having a closed cellrigid foam float may be attached to the bottom of the bowl 115 to adjustthe fluid level within the filter. The float drain 141 includes a floathole 143 that can open and close depending on the level of the float atthe bottom of the bowl 115 (discussed further below).

The filter bowl 115 may be threaded with a tapered filter head 120,which includes both threaded inlet and outlet ports, 125 and 130,respectively. The inlet and outlet ports, 125 and 130, respectively, maybe generally inline with each other, as shown in FIG. 1, for ease ofassembly into a compressed air or gas system. This is because multiplefilter assemblies 100 are often used in compressed gas systems, and itis easier to connect assemblies 100 in series when the inlet and outletports 125 and 130 share the same center line. As such, no elbow ordiverter is needed to connect the multiple filter assemblies 100 andthus, piping the series of assemblies will be made easier and cheaperfrom a manufacturing standpoint.

In example embodiments of the present invention, a pressure differentialexists across the inlet and outlet ports, 125 and 130. In exampleembodiments, the differential pressure may be from 0 to 10 pounds persquare inch (psi) or greater. The filter assembly 100 may also includepressure sensors 134 a, positioned at the inlet and outlet ports, 125and 130, for measuring the pressure differential across the filterelement 110 using a pressure gauge 133. The pressure at the inlet ishigher than the pressure at the outlet and, as such, fluid flows throughthe filter assembly 100 is driven by the pressure differential. Becausethe process flow is pressurized during operation, a bleed orifice 160may be used in such a way as to whistle a warning in the case that anattempt is made to disassemble the assembly 100 while it is underpressure.

In example embodiments of the present invention, the assembly 100includes top cap 135 having a funnel-like configuration for directingflow into the filter element 110. The top cap 135 is generallyhorn-shaped, allowing for a smooth transition of the flow into the media112 resulting in lower overall pressure loss across the inlet and outletstreams. The top surface of top cap 135 may have a curved lip portiondescribed as non-planar flange portion 105. The non-planar flangeportion 105 incorporates a “modified venturi” having a generallydiagonal entrance facing the process flow inlet for improved in-to-outflow through the filter element 110. The non-planar flange portion 105is generally s-shaped, or shaped like an ogee, wherein a top-most end105 a and a bottom-most end 105 b of the non-planar flange portion 105are substantially perpendicular with the inner side wall of the filterhead 120 and therefore, form a seal with the inner side wall.

In example embodiments of the present invention, a seal 137 is formedbetween the top cap 135 and the filter head 120 by mating the top cap135 with the inner wall of the filter head 120 along the non-planarflange portion 105 to form seal 137, as shown in FIG. 1. Accordingly,all the process flow is driven down into the element 110. In exampleembodiments of the present invention, the filter assembly 100 alsoincludes a bottom cap 150 for sealing fluid within the filter element110, thereby forcing all fluid that enters the filter element 110 topass through the filter media 112 from the inside out.

In example embodiments of the present invention, seal 137 may be formedwith the help of a compression tab 145 on the bottom portion of the topcap 135. The compression tab 145 serves the dual purpose of maintainingthe proper squeeze (pressure) on the seal 137 while also ensuring properpositioning of the filter element 110 during assembly of the filterassembly 100. In example embodiments of the present invention, acompression tab 145 may be located below the outlet port 130. Thecompression tab 145 may apply a squeeze to the top cap 135 at thetop-most 105 a and bottom-most ends 105 b of the non-planar flangeportion 105. In some embodiments, the compression tab 145 may becomeseated against the filter bowl 115 due to being pushed down as a resultof the pressure differential.

The compression tab 145 is seated such that it encloses the top portionof each component of the filter element 110, as shown in FIG. 1, toensure that the inlet fluid flowing into the filter element 110 and outthrough the media 112. The compression tab 145 positions the filterelement 110, ensuring that the required force for sealing the filterelement 110 within the assembly 100 is applied. The compression tab 145is positioned to sit just above the top edge of the bowl 115 once thefilter has been assembled so as to keep the element 110 from slidingdownward and breaking the pressurized seal. In other embodiments of thepresent invention, the filter assembly 100 may include more than onecompression tab 145.

FIG. 2 provides an exploded view of the inner components of the filterassembly of FIG. 1. These inner components include the top cap 135, thebottom cap 150 and the individual components of the filter element 110.In addition to the compression tab 145, the top cap 135 may have agroove 207, as shown in FIG. 2, for an o-ring (not shown) which may alsobe used to help maintain the seal 137. This o-ring seal isolates thethreads, which are used in attaching the filter head 120 to the bowl115, from the fluid reducing the possible corrosive effect on thethreads.

The bottom cap 150, used to prevent fluid from flowing through thefilter element 110 without passing through the media 112, may also havean outer lip portion 150 a which mates to form a seal with the drainlayer 117 and an inner lip portion 150 b which is sized to fit withinthe inner surface of the filter media 112. The bottom end cap 150 issolid (closed off) effectively sealing fluid within the filter element110, such that all fluid that enters the filter assembly 100 must passradially through the filter media 112 or in the case of a granular typebed of media, the bottom end cap 150 may be open allowing axial flowthrough the bed. The bottom cap 150 may be adhered to the drain layer117 using epoxy adhesive or urethane adhesive to seal.

In example embodiments of the present invention, the filter element 110may be housed within the filter bowl 115 and which encloses: the filtermedia 112 surrounded by porous, louvered or perforated metal supporttubes 140; the top cap 135 and the bottom end cap 150. The filter mayinclude one, two or more porous, louvered or perforated support tubes140 designed to support the inner and/or the outer surfaces of a filtermedia 112 without impeding flow through the filter element 110 whilerigidly linking the top cap to the bottom cap. In example embodiments,the filter element 110 includes two support tubes, as shown in FIG. 2.The support tubes 140 may be made of metal or plastic or alternatively,a wire screen that is suitable for providing support to the filter media112 may be used.

In example embodiments of the present invention, the filter media 112may be cylindrical wrapped and/or pleated media or alternatively agranular bed of media. The filter media may be made of borosilicateglass and/or various hydrocarbon based materials depending on thedesired filtration. A common media is made of borosilicate glass fiberstreated with hydrophobic and or oleophobic matter to assist in thecoalescing of contaminants and trapping of particulates. In exampleembodiments of the present invention, several different grades ofborosilicate glass or nanofibers may be added to progressively removesolid particulates in the fluid inlet stream in addition to causingfluids to coalesce out of the fluid inlet stream as it passes throughthe media 112.

In example embodiments of the present invention, in addition to orinstead of coalescing media, activated carbon may be used within themedia 112 in order to remove contaminants, such as organic vapors, andodors from the fluid stream. The addition of activated carbon may haveapplication in systems for purifying breathing air, for example.

Because pleating increases the surface area of the media 112 and allowsfor more uniform air to flow through the media 112, spun bondedpolyester and nylon scrims may be added to assist in pleating processand maintain separation between pleats of the media 112. In exampleembodiments of the present invention, the media may include at least:borosilicate glass fibers, activated carbon fibers, polyester fibers,polypropylene fibers, nylon fibers, spun bonded scrim and/or similarmedia.

FIG. 3A provides a plan view of the filter assembly of FIG. 1 and FIG.3B provides a plan view of the filter assembly of FIG. 1 without thedifferential pressure gauge. In example embodiments, a differentialpressure gauge 133, best shown in FIGS. 3A and 7, measures the pressuredifferential across the filter element 110. The sensors 134 a of thegauge 133 are attached to the filter head 120 via ports 134 b, as bestshown in FIGS. 3A and 3B. An overall pressure differential drives fluidthat enters the assembly 100 through the filter element 110, from theinlet port 125 ultimately out through the outlet port 130. The ports 134b may be threaded for attachment of the pressure gauge 133 and sensors134 a. An o-ring groove 344 for attachment of ganging clamps (not shownin FIGS. 3A and 3B) may be found on the inlet and outlet ports 125 and130. Ganging clamps are used to attach multiple filter assemblies 100,as discussed below.

In example embodiments of the present invention, the top outer surfaceof the filter head 120 has a slanted cylindrical configuration having adiagonal inner top surface 127, as shown in FIGS. 1, 3A and 4A. Theinner top surface 127 is slanted in order to minimize the volume of thefilter head 120, which may be desired in certain applications. FIG. 4Aprovides an angled plan view of the top of the filter head 120 of thefilter assembly 100 and FIG. 4B provides an angled plan view of thebottom of the filter head 120 of the filter assembly 100. In examplemethods of using the filter assembly, fluid enters the filter head 120at the inlet port 125. The top inner surface of the filter head 120 hasa sloped portion 428 that curves to compliment the inlet port 125, asbest shown in FIG. 4B. The fluid outlet flows out of the filter head 120through the outlet port 130. As would be appreciated by one of ordinaryskill in the art, the filter head 120 of the present invention is novelin its simplicity because there is no need for a diverter component todirect flow into and out of the filter assembly 100.

In example embodiments, a cosmetic top cover 555, as best shown in FIG.5, may be fitted to compliment the slanted top surface 127 of the filterhead 120 for esthetic reasons. The top cover 555 would include accessports 557 for attaching sensors 134 a to the differential pressure gauge133 through the filter head 120. The top cover 555 may be made ofplastic, metal or any other suitable material. In example embodimentsthe cover is made of plastic.

Referring now to FIGS. 6A-6C, various views of the filter bowl 115 areprovided. Another inventive feature of the present invention is that, inexample embodiments, the filter bowl 115 may contain shallow inner ribs665 running axially along the inside surface of the filter bowl 115, asshown in FIGS. 6A and 6C, for capillary draining of liquid drops thatmay escape the drain layer 117. For instance, the inner ribs 665 may actas a capillary to drain oil droplets that form on the inside wall of thefilter bowl 115 as the amount of oil within the drain layer 117 buildsup. As such, the inner ribs 665 force the oil droplets, using capillaryaction along with gravitational force, to continue to flow down into thefloat drain 141 and keep the coalesced oil from re-entraining in theoutlet fluid stream. In example embodiments of the present invention,outer ribs 680 may be located on the outer surface of the filter bowl115 to aid in disassembling the filter housing by hand, for instance,when the filter media 112 needs to be replaced.

In example embodiments of the present invention, a baffle 670 may belocated along the bottom inner portion of the filter bowl 115 forenhancing dead air space to prevent re-entrainment of the coalescedfluid into the product gas stream. The baffle 670 achieves this byminimizing air circulation that otherwise would result in more turbulentair that would sweep unwanted coalesced liquids back into the productgas stream. The baffle 670 also ensures that the filter element 110 ismaintained in a correct position within the element 110. In otherexample embodiments, the bottom cap 150 may be rested upon the baffle670.

In example embodiments of the present invention, the filter bowl 115 mayalso include a drain hole 675 for draining fluids from the filterassembly 100 through the float drain 141 which is attached to the bottomof the filter bowl 115. The float drain 141 may have a snap action forvery reliable open/close feature to ensure that none of the productstream may be lost from the outlet stream. Additionally, a sight glass684 (not shown) may be located near the bottom of the bowl 115 forviewing the fluid level within the float drain 141.

In example embodiments of the present invention, another o-ring (notshown) or some similar sealing mechanism may be present to complete thepressurized attachment between the filter bowl 115 and the filter head120. The o-ring seal may also have the effect of preventing contaminantsfrom reaching the attaching threads, minimizing corrosion and galling inthe threads. An o-ring groove 683 for seating the o-ring may be locatedat the top of the filter bowl 115, as shown in FIG. 6B.

In example embodiments of the present invention, contaminated fluidenters the filter head 120 of the filter assembly 100 through the inletport 125. The filter top cap 135 directs fluid from the inlet port 125,along the inner surface of its horn-shaped structure, and into thefilter element 110. The inlet fluid would then flow radially out througha cylindrical wrapped or pleated media 112 or alternatively, the fluidcould flow axially through a bed of granular-type media 112. The productoutlet gas stream would then flow up through the annular space betweenthe filter element 110 and housing 115, being smoothly directed by thebottom portion of the element top cap 135 in the filter head 120 and outof the filter assembly 100 through the outlet port 130.

In certain applications, the media 112 affects adsorption of condensablehydrocarbons and odors within the inlet stream. In coalescing filters,the drain layer 117 has an effect of facilitating the effect of gravityin causing the condensed fluids to drop down into the float drain 117rather than flowing into the outlet gas stream. The drain layer 117 maybe made of open shell foam or needle point felt like polyester or anyother material suitable for absorbing coalesced fluids.

The condensed fluid should be drained from the filter assembly 100before the liquid level reaches the height of the filter element 110.When draining is needed, the float drain 141 lifts up to allow liquid todrain out of the assembly 100. The mechanism of the float drain 141operates as snap valve, which in some embodiments is magnetic,controlled by the high density foam float 141. When the float 141 rises,as the fluid level rises to a certain height, the valve opens to allowliquid to drain and then shuts off before any product gases escape thefilter assembly 100. In example embodiments, the float drain 141 mayhave a brass stem with o-ring seal for attachment into the filter bowl115.

In certain applications, it may be desirable to use more than one filterassembly 100 in series to achieve the required degree of filtration. Thefilter assembly 100 may be attached to a second assembly via gangingclamps 785 attached to inlet port 125 and outlet port 130, as shown inFIG. 7. The ganging clamps 785 may also have tapered sides 787 to“squeeze” the flanges 105 of each filter assembly 100 together. Thefilter heads 120 include an o-ring groove 344 to provide space for ano-ring (not shown) which forms a seal between the inlet and outlet ports125 and 130. In these embodiments, the inlet and outlet ports 125 and130 may have alignment tabs 790 for facilitating the connection of theganging clamps 785 to the filter head 120. The ganging clamps would havea complimentary indexing key 795 for mating with the alignment tabs 790.The ganging clamps may also include holes 797 for bracket fasteners (notshown) which may be used in wall mounting the assembly 100.

It is understood that, although the filter assembly 100 of the presentinvention is described as relating to in-to-out flow through thecylinder filter media, the filter assembly 100 may also be reversedusing out-to-in flow in some applications with similar results inpressure loss and improved performance due to the non-planar flange 105.For instance, out-to-in flow would be appropriate in applications wherethere may be particulate high dust loading capacity so that caked ondirt can drop to the bottom of the bowl 115.

The many features and advantages of the invention are apparent from thedetailed specification, and thus, it is intended by the appended claimsto cover all such features and advantages of the invention which fallwithin the true spirit and scope of the invention. Further, sincenumerous modifications and variations will readily occur to thoseskilled in the art, it is not desired to limit the invention to theexact construction and operation illustrated and described, andaccordingly, all suitable modifications and equivalents may be resortedto, falling within the scope of the invention.

1. A method of directing flow through a filter assembly, comprising:directing flow of a fluid into an inlet port located within a filterhead of the filter assembly; passing the fluid from the inlet port intoa filter element using a top cap having a substantially curved,non-planar flange portion, wherein the non-planar flange portion has agenerally s-shaped cross-sectional profile and is sealingly receivedwithin the filter head such that the filter head is divided into inletand outlet partitions; and passing the fluid out of the assembly throughan outlet port.
 2. The method of directing flow through a filterassembly of claim 1, further comprising directing the fluid through abarrier of filtration media of the filter element.
 3. The method ofdirecting flow through a filter assembly of claim 1, further comprisinghand tightening a filter bowl to the filter head using outer ribsrunning along an outside surface of the filter bowl.
 4. The method ofdirecting flow through a filter assembly of claim 1, further comprisingforming a pressurized attachment between a filter bowl and the filterhead.
 5. The method of directing flow through a filter assembly of claim1, further comprising minimizing re-entrainment of coalesced fluid usinga baffle located along a bottom inner portion of a filter bowl.
 6. Themethod of directing flow through a filter assembly of claim 1, furthercomprising connecting the filter assembly to at least one otherfiltration apparatus using a plurality of ganging clamps.
 7. The methodof directing flow through a filter assembly of claim 1, furthercomprising clipping the filter element using a compression tab.
 8. Themethod of directing flow through a filter assembly of claim 1, furthercomprising sealing the filter head to the top cap using a compressiontab.
 9. A filter assembly comprising: a filter head having inlet andoutlet ports; and a top cap having a substantially curved, non-planarflange portion, the non-planar flange sealingly received within thefilter head such that the filter head is divided into inlet and outletpartitions, wherein the flange portion has a generally s-shapedcross-sectional profile.
 10. The filter assembly of claim 9, wherein theinlet and outlet ports are generally inline with one another.
 11. Thefilter assembly of claim 9, wherein the filter head includes a slantedinner top surface for decreasing a volume of the filter head.
 12. Thefilter assembly of claim 9, further comprising a filter bowl attached tothe filter head and a filter element housed within the filter bowl. 13.The filter assembly of claim 12, wherein the filter bowl includes innerribs running axially along an inside surface of the filter bowl forcapillary draining of liquid drops that escape a drain layer whichcomprises an outermost portion of the filter element.
 14. The filterassembly of claim 12, wherein the filter bowl includes an o-ring groovelocated along an upper outer surface of the filter bowl for forming apressurized attachment between the filter bowl and the filter head. 15.The filter assembly of claim 12, wherein the filter element includes abarrier of filtration media, a drain layer and at least one supporttube.
 16. The filter assembly of claim 9, further comprising at leastone compression tab configured to maintain a compression seal betweenthe filter head and the top cap.
 17. The filter assembly of claim 9,further comprising at least one compression tab configured to positionthe filter element.
 18. The filter assembly of claim 9, wherein theflange portion incorporates a modified venturi.
 19. The filter assemblyof claim 9, further comprising at least one ganging clamp for connectingthe filter assembly to at least one other filtration apparatus.
 20. Afilter assembly comprising: filter head means for containing inlet andoutlet ports; filter element means for filtration of a fluid; filterbowl means for housing the filter element, wherein the filter bowl meansis attached to the filter head means; and top cap means for dividing thefilter head into inlet and outlet partitions; wherein the top cap meansincludes a substantially curving non-planar flange portion sealinglyreceived within the filter head, wherein the flange portion has agenerally s-shaped cross-sectional profile.